资源简介

(共15张PPT)
Unit 4
Hands-on fun
Word power
To master the meaning and word formation rules of the negative prefixes un-, in-, im-.
01
学习目标
To use words with negative prefixes un-, in-, im- correctly.
02
They means “not”.
Andrew thought he was unlucky to fill the room with water. Suzy thought Andrew’s ways are incorrect. Andrew bought many books about DIY and took an online DIY course as well. Now no DIY seems impossible to him.
What can you find by looking at the words in bold
They all have prefixes: un-, in-, im-.
Lead in
One of the most common prefixes for adjectives is un-. It means “not”. We add it to some adjectives to give them the opposite meaning. We can also use some other prefixes, such as in- and im-, to form new adjectives with the opposite meaning.
新课讲授
Presentation
Adjective +Prefix →Adjective
lucky + un →unlucky
correct + in →incorrect
possible + im →impossible
Adjective +Prefix →Adjective
usual + un →unusual
complete + in →incomplete
polite + im →impolite
Do you know other words with the same prefix〝un-〞
un- 加在形容词前，让词义变成“不……的”
happy
fair
friend
important
unhappy（不开心的）
unfair（不公平的）
unfriendly（不友好的）
unimportant（不重要的）
Do you know other words with the same prefix〝in-〞
in- 加在形容词前，也表示“不……的”
correct
complete
visible
active
incorrect（不正确的）
incomplete（不完整的）
invisible（看不见的）
inactive(不积极的)
Do you know other words with the same prefix〝im-〞
im- 常用于以“b” “m”或“p”开头的单词前
patient
polite
possible
impatient（不耐烦的）
impolite（不礼貌的）
impossible（不可能的）
un-、im-和in-前缀
前缀是指添加在一个单词前形成一个新的单词的一个字母或者一组字母。
un-是最常见的形容词前缀之一。它的意思是“不”。我们把它加到一些形容词中，赋予它们相反的意思。
除了un-，我们也可以使用一些其他的前缀，如in-和im-来组成意思相反的新单词。
其他否定形容词前缀
除了un-、im-和in-前缀之外，还有一些加在形容词前面形成相反意思的形容词的前缀：
1. dis-
honest (诚实的)→dishonest (不诚实的)
2. ab-
normal (正常的)→abnormal (反常的)
3. ir-
regular (规则的)→irregular (不规则的)
4. il-
legal (合法的)→illegal (不合法的)
5. non-
existent (存在的)→non-existent (不存在的)
A Add the correct prefixes to the words below so that they have
opposite meanings. You may use a dictionary to help you.
1 interesting _____________ 2 sure _____________
3 able _____________ 4 friendly _____________
5 active _____________ 6 patient _____________
7 expensive _____________ 8 perfect _____________
uninteresting
unsure
unable
unfriendly
inactive
impatient
inexpensive
imperfect
Practice
B Read the conversations below. Fill in the blanks with the words in the
box, adding the correct prefixes to them.
correct tidy usual possible patient
1 Simon: Do you spend much time doing DIY, Nora
Nora: Yes, I do! It’s ________ to find me without a DIY job to do.
What about you
Simon: I’m not a fan of DIY because I’m too ___________.
Nora: Oh yes, it’s _________ to finish a DIY job if you are not patient.
unusual
impatient
impossible
2 Mum: Suzy, your room is really ________—things are all over the floor.
Suzy: Sorry, Mum. I’ll tidy up soon. It seems some of the answers in my homework are _________. I’m looking for my textbooks to check.
untidy
incorrect
C Write about your and your friends’ DIY jobs, using the prefixes un-, in- and im-.
Last weekend, my friend Lisa and I did some DIY jobs. I tried to fix a chair, but it was unstable and fell apart. Lisa painted a wall, but it was incomplete because she ran out of paint. Next time, we'll plan better and make sure nothing is incorrect. Then it will be impossible for us to fail!
1.The toy car was ____________ (complete) — it had no wheels!
2.Jim has gone to bed This is very _________ (usual). He always stays up late.
3.If you find the answer __________ (correct), you can cross it and try to find the right one.
4.Don't leave us alone. We all find it __________ (possible) to finish the task without your support.
5.The rainy day made everyone __________ (happy).
6. It’s __________ (polite) to talk with your mouth full of food!
incomplete
unusual
impossible
unhappy
incorrect
根据句意及提示完成下列句子
impolite
当堂检测
Homework
Write sentences with the words using the prefixes: un-/in-/im-correctly.
Preview Unit 4 Integration.

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